\begin{table}%t4
\par
\caption {\label{table:energies}Target state energies for our two configuration sets (1350 and 1044) compared to available NIST data.}
%\centering
\par
\begin{tabular}{rl@{\extracolsep{0.5cm}}c@{\extracolsep{0.5cm}} 
c@{\extracolsep{0.1cm}}c@{\extracolsep{0.5cm}}
c@{\extracolsep{0.1cm}}c}
\hline\hline\\[-5pt]
  \multicolumn{2}{c}{}&\multicolumn{5}{c}{Energy in Ryd (Difference from NIST)} \\[0.1cm]
  \cline{3-7}\\[-6pt]
  \multicolumn{2}{c}{$LS$ state} & NIST & \multicolumn{2}{c}{This work:1350} & \multicolumn{2}{c}{This work:1044} \\[5pt] 
\hline \\[-3mm]
1  & 2s$^2$2p$^4$~$^3$P                              & 0.0000 & 0.0000 & (0.0000) & 0.0000 & (0.0000) \\
2  & 2s$^2$2p$^4$~$^1$D                              & 0.3194 & 0.3356 & (0.0162) & 0.3360 & (0.0166) \\
3  & 2s$^2$2p$^4$~$^1$S                              & 0.6962 & 0.7082 & (0.0120) & 0.7084 & (0.0122) \\
4  & 2s2p$^5$~$^3$P$^{\rm o}$                        & 2.5802 & 2.5624 & (0.0089) & 2.5572 & (0.0230) \\
5  & 2s2p$^5$~$^1$P$^{\rm o}$                        & 3.6142 & 3.6288 & (0.0146) & 3.6270 & (0.0130) \\
6  & 2p$^6$~$^1$S                                    & 6.0334 & 6.0140 & (0.0194) & 6.0020 & (0.0314) \\
7  & 2s$^2$2p$^3$($^4$S$^{\rm o}$)3s~$^5$S$^{\rm o}$ & --      & 6.0890 & --        & 6.0744 & --        \\
8  & 2s$^2$2p$^3$($^4$S$^{\rm o}$)3s~$^3$S$^{\rm o}$ & 6.2300 & 6.2346 & (0.0046) & 6.2244 & (0.0056) \\
9  & 2s$^2$2p$^3$($^2$D$^{\rm o}$)3s~$^3$S$^{\rm o}$ & 6.6238 & 6.6676 & (0.0438) & 6.6542 & (0.0304) \\
10 & 2s$^2$2p$^3$($^4$S$^{\rm o}$)3p~$^5$P           & --      & 6.6776 & --        & 6.6630 & --        \\
11 & 2s$^2$2p$^3$($^2$D$^{\rm o}$)3s~$^1$D$^{\rm o}$ & 6.6948 & 6.7402 & (0.0454) & 6.7290 & (0.0342) \\
12 & 2s$^2$2p$^3$($^4$S$^{\rm o}$)3p~$^3$P           & --      & 6.8104 & --        & 6.7982 & --        \\
13 & 2s$^2$2p$^3$($^2$P$^{\rm o}$)3s~$^3$P$^{\rm o}$ & 6.8868 & 6.9500 & (0.0632) & 6.9366 & (0.0500) \\
14 & 2s$^2$2p$^3$($^2$P$^{\rm o}$)3s~$^1$P$^{\rm o}$ & 6.9598 & 7.0256 & (0.0658) & 7.0144 & (0.0546) \\
15 & 2s2$^2$p$^3$($^2$D$^{\rm o}$)3p~$^1$P           & --      & 7.1896 & --        & 7.1748 & --        \\
16 & 2s$^2$2p$^3$($^2$D$^{\rm o}$)3p~$^3$D           & --      & 7.2110 & --       & 7.1962 & --        \\
17 & 2s$^2$2p$^3$($^2$D$^{\rm o}$)3p~$^3$F           & --      & 7.2560 & --        & 7.2430 & --        \\
18 & 2s$^2$2p$^3$($^2$D$^{\rm o}$)3p~$^1$F           & --      & 7.2784 & --        & 7.2660 & --        \\
19 & 2s$^2$2p$^3$($^2$D$^{\rm o}$)3p~$^3$P           & --      & 7.4042 & --        & 7.3924 & --       \\
\hline\\[-5pt]
\end{tabular}
\end{table}